Various builtins a require an integer constant. Not providing

one results in an obscure error from the backend that doesn't make
sense.  Capture this information in the .def files for builtins with
a new "I" modifier letter indicating the an argument needs to be an ICE.

Nothing uses this yet, but sema will eventually enforce this (eliminating
some special cases from semachecking.cpp) and codegen will use this to 
force an ICE value, preventing backend error messages.

llvm-svn: 115302

3 files changed, 15 insertions, 7 deletions

diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def
index d0459101c08..ca710423d91 100644
--- a/clang/include/clang/Basic/Builtins.def
+++ b/clang/include/clang/Basic/Builtins.def
@@ -38,12 +38,13 @@
 //  SJ -> sigjmp_buf
 //  . -> "...".  This may only occur at the end of the function list.
 //
-// Types maybe prefixed with the following modifiers:
+// Types may be prefixed with the following modifiers:
 //  L   -> long (e.g. Li for 'long int')
 //  LL  -> long long
 //  LLL -> __int128_t (e.g. LLLi)
 //  S   -> signed
 //  U   -> unsigned
+//  I   -> Required to constant fold to an integer constant expression.
 //
 // Types may be postfixed with the following modifiers:
 // * -> pointer (optionally followed by an address space number)
@@ -367,7 +368,7 @@ BUILTIN(__builtin___vfprintf_chk, "iP*icC*a", "FP:2:")
 BUILTIN(__builtin___vprintf_chk, "iicC*a", "FP:1:")
 
 BUILTIN(__builtin_expect, "LiLiLi"   , "nc")
-BUILTIN(__builtin_prefetch, "vvC*.", "nc")
+BUILTIN(__builtin_prefetch, "vvC*.", "nIc")
 BUILTIN(__builtin_trap, "v", "nr")
 BUILTIN(__builtin_unreachable, "v", "nr")
 BUILTIN(__builtin_shufflevector, "v."   , "nc")
diff --git a/clang/include/clang/Basic/BuiltinsX86.def b/clang/include/clang/Basic/BuiltinsX86.def
index 025e7b60c23..8a730a836b6 100644
--- a/clang/include/clang/Basic/BuiltinsX86.def
+++ b/clang/include/clang/Basic/BuiltinsX86.def
@@ -97,7 +97,7 @@ BUILTIN(__builtin_ia32_pcmpgtd, "V2iV2iV2i", "")
 BUILTIN(__builtin_ia32_maskmovq, "vV8cV8cc*", "")
 BUILTIN(__builtin_ia32_pmovmskb, "iV8c", "")
 BUILTIN(__builtin_ia32_movntq, "vV1LLi*V1LLi", "")
-BUILTIN(__builtin_ia32_palignr, "V8cV8cV8cc", "")
+BUILTIN(__builtin_ia32_palignr, "V8cV8cV8cIc", "")
 BUILTIN(__builtin_ia32_vec_init_v2si, "V2iii", "")
 BUILTIN(__builtin_ia32_vec_init_v4hi, "V4sssss", "")
 BUILTIN(__builtin_ia32_vec_init_v8qi, "V8ccccccccc", "")
@@ -255,8 +255,8 @@ BUILTIN(__builtin_ia32_psraw128, "V8sV8sV8s", "")
 BUILTIN(__builtin_ia32_psrad128, "V4iV4iV4i", "")
 BUILTIN(__builtin_ia32_psrlw128, "V8sV8sV8s", "")
 BUILTIN(__builtin_ia32_psrld128, "V4iV4iV4i", "")
-BUILTIN(__builtin_ia32_pslldqi128, "V2LLiV2LLii", "")
-BUILTIN(__builtin_ia32_psrldqi128, "V2LLiV2LLii", "")
+BUILTIN(__builtin_ia32_pslldqi128, "V2LLiV2LLiIi", "")
+BUILTIN(__builtin_ia32_psrldqi128, "V2LLiV2LLiIi", "")
 BUILTIN(__builtin_ia32_psrlq128, "V2LLiV2LLiV2LLi", "")
 BUILTIN(__builtin_ia32_psllw128, "V8sV8sV8s", "")
 BUILTIN(__builtin_ia32_pslld128, "V4iV4iV4i", "")
@@ -273,7 +273,7 @@ BUILTIN(__builtin_ia32_pmaddwd128, "V8sV8sV8s", "")
 BUILTIN(__builtin_ia32_monitor, "vv*UiUi", "")
 BUILTIN(__builtin_ia32_mwait, "vUiUi", "")
 BUILTIN(__builtin_ia32_lddqu, "V16ccC*", "")
-BUILTIN(__builtin_ia32_palignr128, "V16cV16cV16cc", "") // FIXME: Correct type?
+BUILTIN(__builtin_ia32_palignr128, "V16cV16cV16cIc", "") // FIXME: Correct type?
 BUILTIN(__builtin_ia32_insertps128, "V4fV4fV4fi", "")
 
 BUILTIN(__builtin_ia32_storelv4si, "vV2i*V2LLi", "")
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 57780ef981c..ce76fcd9ba4 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -5187,12 +5187,16 @@ static QualType DecodeTypeFromStr(const char *&Str, ASTContext &Context,
   // Modifiers.
   int HowLong = 0;
   bool Signed = false, Unsigned = false;
-
+  bool RequiresIntegerConstant = false;
+  
   // Read the modifiers first.
   bool Done = false;
   while (!Done) {
     switch (*Str++) {
     default: Done = true; --Str; break;
+    case 'I':
+      RequiresIntegerConstant = true;
+      break;
     case 'S':
       assert(!Unsigned && "Can't use both 'S' and 'U' modifiers!");
       assert(!Signed && "Can't use 'S' modifier multiple times!");
@@ -5362,6 +5366,9 @@ static QualType DecodeTypeFromStr(const char *&Str, ASTContext &Context,
         break;
     }
   }
+  
+  assert((!RequiresIntegerConstant || Type->isIntegralOrEnumerationType()) &&
+         "Integer constant 'I' type must be an integer"); 
 
   return Type;
 }